#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
/*int main() {
	int f = 0;
	int x;
		scanf("%d", &x);
	if (x < 0) {
		f = -1;
	}
	else if (x == 0)
		f = 0;
	else f = 2 * x;
	printf("%d", f);
	return 0;
}*/

/*int main() {
	int grade;
	scanf("%d", &grade);
	grade /= 10;
	switch (grade) {
	case 10:
	case 9:printf("A"); break;
	case 8:printf("B"); break;
	case 7:printf("C"); break;
	case 6:printf("D"); break;
	default:printf("E"); break;
	}
	return 0;
}*/


/*int main()
{
	int f = 0;
	int x;
	scanf("%d",&x);
	switch (x >= 0) {
	case 1:f = 2 * x; break;
	case 0:f = -1; break;
	}printf("%d", f);
	return 0;
}*/

/*int main()
{
	int x;
	int n = 0;
	scanf("%d", &x);
	x /= 10;
	n++;
	while (x > 0) {
		x /= 10;
		n ++;
	}printf("%d", n);
	return 0;
}*/